Mobile phone radio terminals (referred to as a “mobile terminals”) in a mobile phone system using PHS (Personal Handyphone System), GSM (Global System for Mobile Communications), IMT-2000 (International Mobile Telecommunication 2000), W-CDMA (Wideband Code Division Multiple Access), or the like, are known that enable a removable memory card to be inserted, and user information, data downloaded via a radio channel, data stored in memory installed in the terminal, and so forth, to be recorded. Also, mobile terminals of a mobile terminal system are known in which a memory card with an IC function such as a GSM SIM (Subscriber Identity Module) or an IMT-2000 or W-CDMA UIM (User Identity Module) is inserted in a removable fashion.
With a mobile terminal allowing insertion of such a memory card or memory card with an IC function, there are no particular restrictions on the removal of a memory card or memory card with an IC function. Therefore, if a terminal from which a memory card or memory card with an IC function has been removed is left lying around, is lost, or is otherwise separated from its user, there is a risk of improper use. Similarly, if a memory card or memory card with an IC function that has been removed from a terminal is left lying around, is lost, or is otherwise separated from its user, there is a risk of internally stored information being improperly read by means of another reading apparatus or the like.
Various measures have therefore been considered for locking a mobile terminal function or memory card function.
For example, as a terminal-side functional restriction, Patent Document 1 describes performing mobile phone dial locking using an operating section of an external apparatus. Also, Patent Document 2 discloses a mobile phone allowing insertion of a UIM card that is configured so that the mobile phone is enabled for use (unlocked) when a UIM card is inserted into a socket of the mobile phone. Furthermore, Patent Document 3 discloses a technology that locks a card inserted in a radio terminal. With a radio terminal according to Patent Document 3, when a user requests removal of an IC card 2, user authentication is performed by a removal authorization processing section. If the authentication is not OK, the IC card is locked, and if the IC card 2 is removed from the radio terminal 1 in this state, the IC card control section in the IC card prevents the contents of information stored in the memory section from being viewed.    Patent Document 1: Japanese Patent Publication No. 3022832    Patent Document 2: Japanese Patent Publication No. 3576977    Patent Document 3: Unexamined Japanese Patent Publication No. 2002-9921